Why has St. Andrews University become a popular school for US students? How can you apply? The Scottish system is closer to that of the US and it is easier to get into and adapt to than US universities.
The system is between the English and US approach. In England, it is usually 3 years and you study one subject. In Scotland, it is 4 years and you start with 2 subjects and cut down to 1 at the end. However, you generally do not have electives outside the subjects you are studying. The Scottish high school examinations are less specialized than the English ones. Understand that the you will still be in a much more structured program than in the US, at least outside of engineering and few other things that are structured in the US.
St. Andrews is probably a top 10 British university, but it is a smaller country with bigger top universities. Oxford, Cambridge, London School of Economics, and Imperial in that order generally rank highest. So St. Andrews is probably about as competitive as a 70th or so ranked US school.
You apply to British universities using a common application. You can apply to at most 5 schools and you cannot apply to both Oxford and Cambridge. There is an essay mainly about how committed you are to the subject you want to study. You should probably apply to other UK universties at the same time, presumably top ones.
It got a lot of publicity and US students due to Prince William attending and meeting Princess Kate there. The royals are not great academically, and it is probably percieved as appropriate for them to go to somewhere with old stone buildings. Most British Universities are very new by US standards. However, it is not “preppy” by US standards. Anyone with the academics can go there and pay relatively low tuition.
The tuition for US students is about $20K/ year and it is hard to get any reductions or aids, so it is more than in state tuition in the US but much less than private colleges and universities.
St. Andrews used the royal publicity to market in the US, showing pictures of the stone buildings at college fairs etc. Unlike English universities, they are willing to talk about GPA, SATs, ECs, etc. However, they are mostly interested in AP exams, like other British and European universities. You need AP exams with good scores.
The students are about 28% Scottish, 27% from elsewhere in the UK, 16% from the US and 29% other international. Most British universities have only a small percentage from the US. Less than 1% of the students are from the US at Oxford and Cambridge.